1. Field of the Invention:
This invention relates in general to valves for controlling the liquid level within a tank.
2. Description of the Prior Art:
Upon storing liquid in a tank, it is often necessary to control the maximum amount of liquid in the tank. For example, some state statutes prohibit filling a tank beyond 80% of its capacity with liquid petroleum gas. Thus, it is desirable to equip such tanks with a device which automatically prevents the tank from being filled in excess of the predetermined level. A variety of control devices have been designed for controlling the flow of liquid or gas. Five such devices are shown by the patents issued to Sperling, U.S. Pat. No. 1,492,272; Norway, U.S. Pat. No. 2,499,409; Browning, U.S. Pat. No. 2,504,638; McGillis et al., U.S. Pat. No. 2,569,110; and Wiseman et al., U.S. Pat. No. 2,431,721. Typically these devices utilize a float valve combination to slowly open or close the fluid inlet port. As a result, the valve when closing may not seat properly on the valve seat.
The devices of Mosher, U.S. Pat. No. 2,854,022 and Brown U.S. Pat. No. 3,756,269 utilize linkages for operably connecting the float to the valve in such a way that the valve will snap shut thereby assuring that the valve seats properly on the valve seat. Although possibly an improvement to the devices listed above, the linkages of Mosher and Brown are perhaps not as dependable and inexpensive as they might be as compared to a simpler design.